Construction of solenoids or coils of wire used in electric machinery



(No Model.) v 3 Shets-Sheet 1.

- G.FO RBES.

CONSTRUCTION OF SOLENOIDS 0R COILSQOF WIRE-USED IN ELECTRIC MACHINERY.

No. 518,946. Patented May 1, 1894.

wil izwsw.

(No Model.) 38heets-Sheet 2 G. FORBES. CONSTRUCTION OF SOLENOIDS 0R GOILS 0P WIRE USED IN ELECTRIC MAGHINERY.

Patented May 1 (No Model.) 3 Sheets-Sheet 3.

G. FORBES.

UONSTR-UGTIONOF SOLENOIDS 0R GOILS 0F WIRE USED IN ELBGTRIG MAGHINERY.

N0. 518,946. Patente ay 1, 1894.

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, ing-coils, and the like.

UNITED STATES PATENT OFFICE.

GEORGE FORBES, OF NIAGARA FALLS, NEW YORK.

CONSTRUCTION OF SOLENOIDS OR COILS 0F WIRE USED IN ELECTRIC MACHINERY.

SPECIFICATION forming part of Letters Patent No. 518,946, dated May 1, 1894.

Application filetlAugust 1'7, 1893. Serial No. 483.358. (No model.)

To wZZ whom it may concern;

Be it known that I, GEORGE FORBES, a subect of the Queen of Great Britain, residing at Niagara Falls,in the county of Niagara and State of New York, have invented certain new and useful Improvements in the Construction of Solenoids or Coils of Wire Used in Electric Machinery; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of my invention is that of keeping cool, and securing a high insulation in, solenoids or coils of wire used for generators, motors, transformers, electro-magnets, chok- WVhen the output of such machines is made very large, it becomes a matter of some difficulty to get from them an output proportional to their size without overheating of the coils. In the case of large developments of power transmission, it also becomes desirable to use very high electricpressures; and the ordinary means available are often insuflicient. My invention enables me to construct machines for use with an electric pressure of twenty thousand volts, or more, and of large output and high efficiency, without any undue heating of the coils. In the ordinary construction of solenoids or coils of wire used in electric machinery, the wire is covered with cotton, or other insulator, and successive layers of wire are sometimes separated by strips of insulating material, the coil being made in any required shape.

My invention consists in inclosing the solenoid or coil, thus built up, in a close fitting covering or casing, and providing inlets and outlets to the casing to admit'of a forced circulation of oil, which, with proper connection as herein shown, affords means whereby the circulating oil saturates the whole of the cotton or insulation and carries away the heat. The oil also increases the insulating quality of the cotton or other covering. I prefer to make the casing for the solenoid or coil by molding a suitable material around the coil. I sometimes use gutta percha or vulcanized rubber, or the material known as woodite. These materials can be molded round the inlet and outlet boxes, so as to make a good joint. If such materials be not available, or if, forany reason, they are unsuitable to special cases,I find it satisfactory to wrap tape round the coils in several layers, each layer being saturated with a suitable material which has good insulating properties and which is not destroyed by oil.

In applying my invention,the oil which, in passing through the coils has become heated, is collected and pumped through pipes cooled by any suitable means, such as laying them in running water or passing them through brine cooled by ammonia. The cool oil can then be forced into the several inlets to the coils. I find it, however, more convenient in practice to pump the cooled oil up to a tank or reservoir, from which pipes lead to the inlets of the coil casing. The oil tank can, in ordinary buildings, be placed at a sufficient height to give enough pressure to force the oil through the coils; and taps may be fixed for regulating the flow of oil. Or, in cases where such a tank cannot be properly placed or where such arrangement is undesirable for other reasons, the cooled oil may be collected in a tank and then forced into the solenoid or coil casing. When a number of coils are thus used in a single machine, the inlet pipes may be connected either in series or in parallel, but generally I prefer to put them in parallel.

In order to judge of the quantity of oil that is passing through each of the coils when the inlet pipes are connected up in parallel, it

is desirable, at a convenient point in the.

outlet pipes, to employ a simple indicator, consisting of a circular box with vanes pivoted at the center, so that the oil in flowing will turn them, and so that, if the box has a glass top, the speed of the vanes can be seen. But for this purpose, I preferably use the device hereinafter shown and described.

Referring to the drawings herewith, consisting of three pagesz-Figure l is an elevation of one of my coils and the connections, a small portion of thecasing and wrapping upon the coil being cut away to show the interior structure. Fig. 2 is a vertical cross-section of one form of pipe joint used upon the solenoid. Fig. 3 is a top plan view of the same. Fig. 4 is an enlarged cross-section of the solenoid or coil and wrapping and casing. Fig.5 is an elevation of one of my coils, constructed after one manner herein described, a small portion of the casing and wrapping upon the coilbe ing cut away to show the interior structure. Fig. 6 is an enlarged crosssection of the same. Fig. 7 is an enlarged elevation of one form of pipe joint used, taken at right angles to the plane of the coil, as shown in Fig. 5. Fig. 8 is an enlarged elevation of the same, taken in the same position as shown in Fig. 5. Fig. 9 is a sectional elevation of an alternating dynamo with stationary armature provided with my invention.

Like letters refer to like parts throughout the drawings.

Figs. 1 and 5 show two methods of building up and constructing solenoids or coils according to my invention. In Fig. 1, A, A, is the Solenoid or coil. This may be built up in any desired manner; but at a, Figs. 1 and 4, I have shown a construction which I have found desirable. About the wires is wound cotton or other insulating material, 1), Figs. 1 and 4E. Closely fitting over this insulation is the casing 0, Figs. 1 and i, which, as has been stated, may be molded and vulcanized over the coil and its insulation and inlet and outlet boxes, of hard rubber, woodite or such material; and in special cases I am enabled to inclose the solenoid in glass or porcelain. I and 0, Figs. 1, 2 and 3, are the inlet and outlet boxes; and in Figs. 2 and 3, is shown the detail construction of wooden joint boxes, made preferably of teak-wood, bolted over the coils, by the bolts d, d, as clearly shown in Figs. 2 and 3. These boxes should be provided with proper joints, such as a screwthread, as shown at c, Fig. 2, for connection with the inlet and outlet pipes. The wires or rods composing the solenoids inclosed within the casing are, in the boxes, I and O, separated from each other by a proper clevice to enable the oil to flow freely to all portions of the coil and follow theinterstices between the wires-but for this precaution there might be'some difficulty experienced in producing the circulation.

Fig. 1 also shows some of the connections and appliances required for the working of my invention. 0 is an inlet tube, connected with a pipe D, D, from which may branch inlet tubes to other solenoids, the pipe D, D, being supplied with oil by a tube E, leading to the reservoir. F is a tube attached to the outlet box, 0; and on this pipe is fixed a tap G, for regulating the flow of the oil, and a device, I-I, for indicating or observing the flow of the oil. This device consists simply in leading the outlet tube F into a cup having transparent sides and which is placed upon and connected with the continuation of the outlet tube which leads into the pipe L. By this means the flow of oil from the tube F can be observed through the transparent sides of the cup. The continuation of the tube F is shown leading into a pipe L, which collects the oil from the other solenoids in the same manner. The pipe L is shown passing through a trough M, containiugrunning water, or brine cooled by ammonia or otherwise. Fromthe pipe L, a tube passes to a pump which raises the oil to the reservoir, from which it flows through the tube E, and so the circulation is maintained.

Fig. 9 shows a sectional elevation of an alternating dynamo, with stationary armature, provided with my invention to show its application. A, A,are thesolenoids, I, I, the inlet boxes, D, is the pipe supported on the crutch K, having the inlet tubes G, O, to supply the coils with oil. 0, O, are the outlet boxes, and F, F, the tubes leading to the pipe L, which is placed within the troughM, within the bed-plate of the dynamo, which serves to carry the cooling water.

In the system of oil circulation shown, the supply of oil is brought downward from the tank, entering the coils and passing out through the outlet tubes,intothecoolingplpes, and is thence pumped back into the tank. Under certain circumstances, especially when the coils occupy a vertical position, I may either substantially reverse the system of 011'- culation, passing the oil directly fromthe pipe in the cooling trough through the pipes F, F, into the coils and so on, or I may reverse the connection of the inlet and outlet tubes with the coils as shown,so as to reverse the direction of the circulation of the oil within the coil casing only, w ithout departing from the spirit of my invention.

Referring now to Figsfo, 6, 7 and 8, I have shown another satisfactory form of casing, with inlet and outlet for oil, which is simple to construct. After the insulated wire has been wound into the required shape, as shown at Ct, Figs. 6 and 7, it is wrapped roun d with tape soaked in any oil resisting medium, which should also have great dielectric strength. The Wrapping of this tape is clearly shown at c, Fig. 5. The inlet I, and the outlet O,in this construction are each made of short lengths of pipe with a screw-thread at one end to connect by a union with the circulating pipes. The pipe is split for some distance at the other end, and is spread out into two branches as is clearly shown in'Figs.7 and 8, which cover a portion of the coil. The tape wrapping is then wound over these ends and about the neck of the pipe in such away as to bind the pipe to the coil and make an oil tight joint. I find in practice that if the temperature of the oil is allowed to rise 20 Fahrenheit in passing through the coils, each ten pounds of oil pumped per minute through the coils is sufficient to carry away the heat equivalent to one horse power wasted in the conductors.

I-Iavin g thus explained the nature of my invention and shown the method of its application, I do not claim as my invention, the placing of wires in pipes filled with stationary oil, nor do I claim the immersion of a transformer or other electrical apparatus in a bath of oil. Nor do I claim herein the armature construction shown in the application of myinvcntion,

as that constitutes the subject matter of a having a close fitting casing and an inlet and separate application for Letters Patent by outlet for oil with means for maintaining a me, filed August 17, 1893, Serial No. 483,357; forced circulation of oil, substantially as but shown. 5 5 VVhatI do claim is- In testimony that I claim the invention 1. The combination of a solenoid or coil above set forth I affix my signature in the with a close fitting casing, having an inlet presence of two witnesses.

and outlet for oil with a pump for maintain- GEORGE FORBES. ing a forced circulation of oil, substantially Witnesses: 10 as described. MORRIS OOHN, J12,

2. The combination of a solenoid or coil 7 O. W. RICKER. 

